For non-porous smooth surfaces, experts use powder-and-brush techniques, followed by lifting tape. Soon after, American police departments adopted the same method and fingerprint identification became a standard practice in the United States.
This pattern is characterized by ridges that enter on one side of the print, loop around, and then exit on the same side. One was Henry Faulds, a Scottish physician who was working as a missionary in Japan in the s. Be sure you have permission to dust on surfaces before you test them.
Ninhydrin causes prints to turn a purple color, which makes them easily photographed. What You Do: Touch a microscope slide with your finger a few times to leave prints.
Four of the five experts changed their opinion. Depending on what city you were tried in, the standards could vary dramatically.